<i>In vitro</i> antioxidant activity and phytochemical screening of methanol extracts of <i>Ficus capensis</i> and <i>Dacryodes edulis</i> leaves

Abstract

In this study, phytochemical screening and in vitro antioxidant activity of methanol extracts of D. edulis and F. capensis leaves were evaluated. Each plant leaves were extracted in methanol using standard procedures. The phytochemical screening of the resulting extracts showed the presence of cardiac glycosides, terpenoids, alkaloids, reducing sugars, steroids, flavonoids and tannins. The in vitro antioxidant assay revealed varied degrees of antioxidant activity of the extracts. The diphenyl -1-picrylhydrazyl (DPPH) radical scavenging capacity was significantly higher (p < 0.05) in D. edulis extract in contrast to that of F. capensis extract (IC₅₀ of 144.9 μg/ml); but was comparable to the standard ascorbic acid (IC₅₀ of 118.55 μg/ml). F. capensis however, showed significantly higher level (p < 0.05) of total phenol (426.5mg gallic acid equivalent/g extract), proanthocyanidin (225.3mg ascorbic acid equivalent/g extract) and lower total flavonoids (46.0mg quercetin equivalent/g extract) content as against D. edulis extract (383.5mg GAE/g, 78.5mg AAE/g, and 78.8mg QE/g, respectively). The ferric reducing antioxidant power (FRAP) was significantly higher (p < 0.05) in D. edulis extract (145.4mg/g extract) when compared with the F. capensis counterpart (120.5mg/g) and was close to that of ascorbic acid standard (140.5mg/g extract). Both extracts showed no significant differences (p > 0.05) in their levels of thiobarbituric acid reactive substances (TBARS). The results suggest that D. edulis and F. capensis leaves possess ample antioxidant activity and phytochemical constituents which may play important roles in the pharmaceutical and food industries.

Keywords: Antioxidant, Dacryodes edulis, Ficus capensis, Phytochemical screening